Described below are various embodiments of polyhedral arrays. Each array is comprised of a plurality of discrete polyhedrons, and a connection network comprising individual connections that interconnect the polyhedrons. The connection network serves to constrain each polyhedron with respect to its six degrees of freedom within three-dimensional space, such as is defined by a three-axis Cartesian coordinate reference frame.
Each polyhedron is discrete relative to adjacent polyhedrons in the array. Thus, each polyhedron is separate from the other polyhedrons, and adjacent polyhedrons do not share common vertices, edges or faces. The connections serve to interconnect the polyhedrons, and when the array is in equilibrium, i.e., at rest and not under an applied load, to maintain them in a spaced apart configuration. When the array is subject to an external influence, e.g. a load such as a force or torque applied to the array, one or more of the polyhedrons may be moved in response to the influence. In some implementations, at least one polyhedron, although constrained by its connections, may move from its equilibrium position into contact with an adjacent polyhedron when the array is subjected to a load. Depending upon the specific implementation, the polyhedron's movement may be a translation, a rotation, or a combination of a translation and a rotation. The ability of a polyhedron to move within the array but remain connected to its neighboring polyhedrons allows the array to have “flexibility” under compression and resist the forces being applied.
In general, the array is three-dimensional and may comprise multiple layers depending on the application and the characteristics desired for the application. Each layer is generally planar, and the layers are generally parallel to each other. The connections extend to adjacent polyhedrons in the same layer and in other layers. The connections can be provided in many different configurations and materials to allow the array to have selected properties.
According to one specific implementation, the connections between the polyhedrons extend along the bias (also described as “in bias directions”). In other words, the connection or connections between a first polyhedron and its nearest neighbor are arranged to extend at acute angles relative to the respective plane or plane(s) of these polyhedrons. In one specific implementation, and as described in greater detail below, the direction of the bias or “bias directions” are oriented at about 45 degrees with respect to the plane or planes. At equilibrium, these bias directions are mutually orthogonal, so any connections in the array that do not extend in parallel directions are also orthogonal with respect to each other. Examples of bias direction arrays, which are discussed below in greater detail, are shown in
According to another implementation, the connections between the polyhedrons are described as radial connections. As used herein, “radial connections” for any given polyhedron extend from a face, edge or vertex of the polyhedron in a direction perpendicular to a vector originating its center. Over its length extending towards an adjacent polyhedron, the radial connection changes direction (or “bends”), as is described and illustrated below, such that its opposite ends are oriented in different planes that are mutually orthogonal to each other. Among other benefits, certain implementations of the radial connection array (hereinafter, “radial array”) allow it to deform such that two or adjacent polyhedrons enter into face to face contact when subjected to a load above a predetermined working load range. Examples of radial direction arrays, which are described below in greater detail, are shown in
According to well known geometry principles, one way polyhedrons are described is in terms of the number of faces, vertices and edges that each type of polyhedron has. For example, an icosahedron has twenty faces, twelve vertices and thirty edges. In a regular icosahedron, each of the twenty faces is an equilateral triangle, so all of the angles are equal and the edges are of equal length. In an irregular polyhedron, however, at least some of the angles and edges are unequal. Certain regular polyhedrons and irregular polyhedrons can be used in arrays, as described below and depending upon the specific implementation.
As described above, the array comprises discrete polyhedrons. In specific implementations, a suitable polyhedron is one that, if circumscribed by a cube, has an edge, a face or a vertex approximately coincident with each of the six cube faces. Stated differently, suitable polyhedrons have at least three pair of connection locations, where each pair of connection locations is mutually orthogonal to the others, and each pair of connection features comprises two opposite faces, two opposite edges, two opposite vertices, or two opposite features of different types (e.g., one face and one opposite edge, or one edge and one opposite vertex).
For example, as shown in
Similarly, as shown in
Referring again to the circumscribing cube, each polyhedron in the array, like an object in space, can be described as having as many as six degrees of freedom, namely the ability to translate in the X, Y and/or Z directions as defined by a fixed coordinate axis (see
Of the five regular Platonic polyhedrons, namely the tetrahedron (4 equilateral triangle faces, 6 edges and 4 vertices), the cube (6 square faces, 12 edges and 8 vertices), the octahedron (8 equilateral triangle faces, 12 edges and 6 vertices), the dodecahedron (12 regular pentagon faces, 30 edges and 20 vertices), and the icosahedron (20 equilateral triangle faces, 30 edges and 12 vertices), only the regular tetrahedron and the regular octahedron do not provide at least three pair of connection locations that are mutually orthogonal to one another (although a special case of the octahedron does meet this criterion). Many other polyhedrons other than the Platonic polyhedrons are also suitable, such as truncated versions of the cube, octahedron and icosahedron (also referred to as a “fullerene” or a “bucky ball”), cubo-octahedrons, dodecahedrons, icosidodecahedrons, rombicosidodecahedrons, snub dodecahedrons, etc. Stellated forms, deltahedrals, dual tetrahedrals and other similar variations of Platonic and Archimedian polyhedrons are also suitable. The specific polyhedrons enumerated here are not to be construed as an exhaustive list, as other polyhedrons having the appropriate number and arrangement of connection features are also suitable
Two important polyhedrons are the icosahedron and the truncated icosahedron. As described above, the icosahedron is a practical choice because it has three pairs of parallel faces. The truncated icosahedron is derived by “slicing off” the twelve vertices of the icosahedron, thereby forming twelve regular pentagons. The truncated icosahedron has twelve regular pentagonal faces, twenty regular hexagonal faces (for a total of 32 faces), 60 vertices and ninety edges. The pentagons and hexagons provide a plurality of pairs of parallel surfaces.
Polyhedrons with fewer rectangular faces (including square faces) are generally more desirable because the triangular faces are more stable than rectangular faces. Although the cube is an acceptable polyhedron with which an array can be formed, in practice, other polyhedrons offer greater advantages.
In some implementations, it is possible to form a mixed array that comprises more than one type of polyhedron. For example, it is possible to form a mixed array having icosahedrons and truncated icosahedrons. Other such mixed arrays are also possible. It is also possible to use polyhedrons of different sizes in the same array, particularly if the differently sized polyhedrons are geometrically scaled relative to each other.
The polyhedrons in the array may be solid, or they may have solid faces that define a hollow interior. One or more faces of a polyhedron may have openings defined therein. It is also possible in some implementations to use polyhedrons having a “wireform” configuration with material defining only the edges and the faces being open. In some implementations, the polyhedrons include enhancements departing from ideal regular forms to facilitate connecting the polyhedrons to each other, such as is described in connection with one implementation shown in
Connections as used herein refers to any matter, including any arrangement of matter (such as a structure), or material that serves as part of the connection network in connecting the polyhedrons together and maintaining their spaced apart configuration in the array at equilibrium. Connections can include mechanical elements, molecules or bonds, such as guest molecules, ligands, ligatures, etc.
Each connection can be a separate element, or multiple connections can be formed together, depending upon the particular geometry, materials and requirements of the array. In arrays with one than one type of connection locations, e.g., vertices and faces, there may be connections extending between a vertex at one end and a face on the opposite end.
As described above, the polyhedral arrays can be designed to withstand loadings within a predetermined working range. For example, the polyhedral arrays can be designed to withstand forces and torques, including compression forces, tensile forces and torsional forces applied to the array, as well as other forces, such as shear forces, that may be developed internally within the array. Bending moments and axial compression forces can also comprise part of the loadings. As described, depending upon the magnitude of the loading, one or more of the polyhedrons in the array may be caused to move from its position at equilibrium.
In addition to withstanding forces, the polyhedral arrays also withstand torques.
The examples of
As described above, one embodiment includes connections oriented on the bias. Relative to a face of the array to which a load is applied (or resolved to apply) in a normal direction, the bias directions are defined to mean directions intersecting the face of the array at an angle. In specific implementations, the bias directions can form angles of about 30 to about 60 degrees with the face of the array. Even better attributes are recognized with bias directions of about 40 to about 50 degrees.
Typically, the bias directions extend at about 45 degrees relative to the face of the array, but can be adjusted in orientation to the applied load. Thus, the bias direction array is in direct contrast with an orthogonal array in which the connections extend at approximately 90 degrees or zero degrees relative to the face of the array. Compared to other orientations, connections extending along bias directions provide robust resistance to shear.
In the array 10, which is shown at equilibrium, the polyhedrons 12 are spaced apart and do not contact each other. In
The polyhedrons 12 in the array 10 have the same general orientation. In the example of
In the array 10, there is a lower layer 20 of polyhedrons generally occupying a first plane, an intermediate layer 22 above the lower layer 20 and generally occupying a second plane and an upper layer 24 above the intermediate layer 22 and generally occupying a third plane. As best seen from the right side of
Each of the polyhedrons 12 in the lower layer 20 and in the upper layer 24 is an edge polyhedron, i.e. a polyhedron occupying an edge position that defines an edge of the array 10. For the intermediate layer 22, the visible edge 12 are along the front right face (five in number) and along the front left face (two in number). Each edge polyhedron has fewer connections to adjacent polyhedrons than an interior polyhedron.
Although not clearly visible in
The connections 14, 16, 18 are shown in
In
For the specific implementation of
The polyhedrons 12 in the example of
As shown in
As shown in
In the radial array, the polyhedrons in the different layers as shown in
The polyhedrons 212 can be provided with predetermined features to facilitate the transformations in shape. In the specific implementation of
The polyhedral arrays described herein are “omni-extensible,” which is to say that an existing array can be extended in any direction by joining additional polyhedrons with additional connections. It is not necessary to first disassemble the existing array before extending it. In the same way that an existing array can be extended, it also possible to join two or more arrays into a single larger array.
When the polyhedral arrays are configured in a regular pattern, the equilibrium locations of the polyhedrons in the array are unique and thus can be specified, e.g., using a Cartesian coordinates or other similar system. Thus, the position of each polyhedron in the array can be described as being “addressable.” In some implementations, at least some portion of the array is capable of carrying or holding electric charge, and the polyhedrons or connections in this portion of the array can be individually addressed to store data and/or to convey signals or transmit power.
As shown in the examples, the polyhedral arrays at equilibrium have spaces separating the polyhedrons. As also described, additional spaces at regularly repeating intervals can also be designed into the array. Depending upon the scale at which the array is constructed, as well as the selected length(s) of the connections relative to the size of the polyhedrons, the resulting array can be designed to provide a desired permeability suitable for a particular application. Thus, an array configured as a building material to be installed in a generally horizontal orientation in an exposed environment can be configured for permeability to rain and storm water, yet still provide the structural strength to support the expected loads for the anticipated design life.
As shown in some of the application examples described below, the configuration of the polyhedral arrays allows for them to interface with other structures, such as, e.g., conventional building materials. Many common conventional building materials have a generally rectangular prism shape, such as conventional bricks, dimensional lumber, plywood and other types of sheet material, etc., which is defined by 90 degree angles. Although most examples of the polyhedral arrays do not terminate at edges defining 90 degree angles, the same mutually orthogonal connection locations of the polyhedrons, some of which are free for edge polyhedrons, can be used for dimensionally reliable and stable attachment to other adjacent materials and structures.
In the described examples, the polyhedral arrays are shown as comprising polyhedrons of the same general size, which is a typical configuration. In some arrays, however, it is possible to mix polyhedrons of different types, or to substitute polyhedrons of different sizes. For example, an array can be formed where the majority of polyhedrons are regular icosahedrons having a unit size, and a larger icosahedron having a size that is a geometric multiple of the unit size is substituted into the array periodically.
A polyhedral array can be configured to be isotropic, i.e., to have the same properties in all directions. Alternatively, the array can have a predetermined anisotropy, e.g., to address a particular requirement of the specific implementation. Also, the polyhedrons and the connections can be isotropic or anisotropic.
The arrays can be configured to have different portions exhibiting different properties. For example, the polyhedrons occupying the edge positions in an array could be formed of a material more resistant to environmental conditions, or specifically adapted for receiving a thin covering layer or attaching to a conventional adjacent structure. Polyhedrons having different physical properties, including elasticity, density, melting point, strength in compression, etc., to name a few, could be substituted in the array to achieve a desired result. Moreover, connections can be adapted in the same way. The properties of the connections can be varied according to their location in the array, their orientation relative to the expected load, etc. In addition, connections can be designed to exhibit different properties along their length.
As an example, the relative rigidities of the polyhedral elements and the connections elements can be tailored for a given application. In addition, individual instances of the same type of element, e.g., the connections, may be provided with varying rigidities to provide a desired anisotropy to the array. For example, connections extending in the “z” direction may be made less or more rigid than the interconnecting members in the “x” and “y” directions where the anticipated loading configuration differs in the “z” direction as compared to the “x” and “y” directions.
In some cases, the polyhedral arrays deviate from perfect regularity yet still have the overall function and behavior of a regular array. In some cases, a polyhedron or a connection may be missing, or there may be a foreign object or impurity present in the array instead of one of the polyhedrons. Indeed, certain implementations warrant slight departures from perfect regularity to account for specific local conditions.
In general, the polyhedrons and connections may be made of any material suitable for the particular application. For large scale applications, familiar materials such as metals, alloys, composites, plastics and others may be used.
It is also possible to provide very small scale arrays, such as at the nanoscale or microscale. Some molecular forms have specific polyhedral geometry. As two examples, the C60 molecule is a truncated icosahedron, and the B12 molecule is an icosahedron. Work in the area of these and similar molecules is represented by U.S. Pat. No. 6,531,107 entitled “Fabrication of Molecular Nanosystems,” U.S. Pat. No. 6,841,456 and U.S. Pat. No. 6,965,026 entitled “Nanoscale Faceted Polyhedra” (these references are incorporated herein by reference). Assembly techniques, such as atomic force microscopy or self assembly, may be used to provide suitable molecules as polyhedral elements. Further, and not appreciated until now, the polyhedral molecules can be arranged into predetermined arrays, such as bias direction arrays or radial arrays, with connections designed as described above and formed of molecules, ligands or ligatures to give the resulting arrays overall properties useful in the design and fabrication of larger arrays (such as lattices) and objects.
According to one specific implementation as shown in
Referring to
In the illustrated embodiment, each of the connection locations 256 is positioned within an opening in a projection 258 protruding slightly from the icosahedral element's outer surface and extending across one of its edges.
As best shown in
As also shown in
The body 264 of the connector can have a spring-shaped construction as shown. Other geometries are, of course, also possible. The spring-shaped body allows the connector to constrain the icosahedral elements 250 to which it is attached, yet can resiliently deform when those icosahedral elements are subjected to a force or a torque.
In the specific embodiment, the icosahedral elements 250 are made of a plastic and have a hollow construction. The connector elements 252 are also made of a plastic.
According to some implementations, providing polyhedrons of a hollow construction can be achieved by providing polyhedron halves having specific geometries. Referring to a specific implementation for the icosahedron shown in
In the array 280, which is also referred to herein as a “trigonal” lattice, the repeating unit 282 is seven polyhedrons, including three connected polyhedrons 284 in the lower layer, three connected polyhedrons 286 in the upper layer, and a single polyhedron 288 in the intermediate layer connected to each of the polyhedrons 284, 286 in the lower and upper layers. From
In the drawings, the spacing between adjacent repeating units 282 has been exaggerated slightly for clarity. In practice, the space between polyhedrons in the lower and upper layers that are adjacent to each other, but of different repeating units, can be the same as the space separating adjacent polyhedrons within the same repeating unit.
The single polyhedron 288 in the intermediate layer is not connected to other intermediate layer polyhedrons. Thus, there is no connection between the intermediate layer polyhedron 288 and an adjacent intermediate layer polyhedron, such as the intermediate layer polyhedron 290. Within the intermediate layer, predetermined recesses or spaces S are defined between the polyhedrons in that layer (and are bounded by the polyhedrons in the lower and upper layers). The spaces S generally occur according to a periodic pattern. The size and frequency of spaces within the array can be selectively determined according to properties desired for the specific application of the array.
As another example,
As shown, the array 292 as illustrated includes two layers of repeating units 294 with six repeating units per layer, for a total of twelve repeating units. Referring to the figures, assuming the exterior polyhedrons of the repeating unit 294 are vertices, the repeating unit is a cubo-octahedron. Thus, the array 292 can be described as a “cubo-octahedron” lattice.
Referring to the figures, each repeating unit 294 is connected to any adjacent repeating unit(s) in the same horizontal “row” or vertical “column.” Among the interconnected repeating units 294 that comprise the array, however, there are predefined spaces T that occur at each intersection of eight repeating units 294. In addition to the full spaces T, there are additional smaller spaces U between at each intersection of four repeating units.
In addition to bias direction arrays and radial arrays, other array configurations are of course also possible, provided that the polyhedrons are discrete from each other at equilibrium and the connections interconnect the polyhedrons and constrain their movement to a desired degree in the resulting array.
The terms and expressions that have been employed in the foregoing specification are used as terms of description and not of limitation, and are not intended to exclude equivalents of the features shown and described or portions of them. In view of the many possible embodiments to which the disclosed principles may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting in scope. Rather, the scope is defined by the following claims. I therefore claim all that comes within the scope and spirit of these claims.
This application is a § 371 U.S. National Stage of International Application No. PCT/US2006/031940, filed Aug. 15, 2006, which was published in English under PCT Article 21(2).
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US06/31940 | 8/15/2006 | WO | 00 | 10/31/2006 |